A Capitol Police officer is suing the department claiming “unlawful retaliation” after she admitted to sharing a photo with Roll Call of a police handgun left in the Capitol Visitor Center’s bathroom.

Jodi Breiterman, a 14-year veteran, was formally demoted from sergeant to private first class in early May, shortly after she returned to duty from a 10-month suspension, according to the lawsuit filed in federal court last week.

[Read: Lawsuit filed by Capitol Police officer] Breiterman, 44, alleges gender discrimination over her suspension and demotion, arguing that other Capitol Police officers received less punishment for committing worse offenses, including the officers who left handguns in bathrooms.

[Related: Capitol Police Left Guns in Bathrooms] She is also claiming a violation of her First Amendment rights, saying she is being punished for sending the photo to the press “because she believed the matter involved serious issues of public safety and was of significant public concern.”

The incident prompted jokes about the Capitol Police on late night television. Breiterman and her attorney declined a request for an interview. Capitol Police also declined to comment.

Breiterman is seeking reinstatement to her former position, lost compensation in excess of $10,000, and additional damages for pain and suffering including legal fees.

A third Glock was found the night of April 16, 2015, by a janitor cleaning the Capitol Police headquarters building on D Street NE. The weapon was left in plain sight, sparking additional concern about the department charged with protecting members of Congress and one of the world's most frequently visited landmarks.

About a month after the story ran, Roll Call reported that a female sergeant had been suspended as retribution for sending the publication a photo of one of the incidents. The sergeant, Breiterman, was one of two senior officials investigated as the source of the photo.

Then-Chief Kim Dine told committee lawmakers a year ago that a six-day suspension for the agent protecting McConnell was “still in the process, but close to being fully adjudicated.” Capitol Police have released no information on disciplinary action in the other two instances.